CMX 600

TheCMX 600was the very firstnon-linear video editing system.This Emmy Award winning system was introduced in 1971 byCMX Systems,a joint venture betweenCBSandMemorex.CMX referred to it as a "RAVE", orRandomAccessVideoEditor.

The 600 had a console with 2 black & white monitors built in, as well as alight penused to control the system. The right monitor, which played the preview video, was used by the editor to make cuts and edit decisions, by using the light pen to select from options which were superimposed as text over the preview video. The left monitor was used to display the edited video.

It recorded and played back black-and-white "skip-field"video in analog on specially modifieddisk packdrives (supplied by Memorex, and which were commonly used to store data digitally on mainframe computers of the time) that were the size of washing machines. The audio was recorded digitally usingPCM,and was recorded by being inserted in the "back porch"of thehorizontal blanking intervalpulses of the video (a technique known as "sound-in-sync"). This audio was somewhat poor, due to a large amount ofjitteroccurring from the signal being played back from the disk packs. The video was also of less than stellar quality, due to it being recorded in skip-field mode (which was done to extend recording time on the disk packs). But all of this did not matter, since the 600's main purpose was solely foroff-line editing,in order to create anEdit Decision List(EDL) for lateron-line editing.

The 600 was paired with the CMX-200, which took the EDL information from the 600, and used it to control severalvideo tape recorders(VTRs) to auto-assemble the video program in the on-line editing stage. The 200 used aTeletype Model 33ASR terminal to input EDL information.

The editing console was interfaced to twoequipment racksof support equipment (which were usually located remotely in another room from the console). The first rack contained the interface electronics for the system, monitoring equipment, and aDigitalPDP-11minicomputerwith 32 kilobytes ofRAM,which controlled the system. The second rack contained all the audio & video electronics, and the "Skip-Field Recorder", which took in video & audio for editing from a VTR, and then recorded such to one or several disk pack drives interfaced to the 600. The CMX 600 could support up to six disk pack drives, for a total recording time of 27 minutes. Each disk pack could record up to 5.4 minutes ofNTSCvideo, or 4.5 minutes ofPALvideo.

The CMX 600 was a system quite ahead of the technology of the time, and was quite expensive, costing about $250,000 USD at its introduction. About 6 systems were manufactured, and were used to edit several television shows and commercials.

See also

• Adrian Ettlinger,an engineer at CBS who conceived and lead the development of the CMX 600.
• SeeCMX Editing Systemspage on Wikipedia.

External links

• A page about the CMX 600, with a demo video available for viewing(Archived copy from archive.org)
• (The demo video mentioned in the above link, on YouTube)
• Timeline, the history of editing(John Buck 2018). (incl complete CMX-600 storyline)(Tablo BooksISBN9781922192295).
• (Free public access to Timeline, the history of editing Analog 1)